Composition for dustproofing coal



Potent-ed l entre@ reirse if il het? einem comprometen non pns'rrnoornue com.

sohn reed mec/'mhelos te Solvay Soles Ecrporation, New York; Y., si corporation ci New Yori; l

No proofing. spontanen may en, rese,

A set-in unseren 'This invention relates to a process for dustproofing coni. More particularly, this invention relstesto en improvement in the art of-dustpro cool with celcium chloride, which improvement permits s reduction in the amount of calcium chloride required vto accomplish effective dustproong and eects the production of substsntially non-corrosive, dustproof coal.

It is well lmown that coal upon handling tends to develop s comderahle quantity or dust 'chiel-i is the come of appreciable nuisance to the hendler oi the Acool end renders the coal. unsightly in appearance, thus detracting from its sales value; hence, the desirabilityofdustproo the coal has long heen recognized. it hss been sug-s gested that to accomplish this purpose ccnl may he treated with e. solution oi culcium chloride so as to form e hygroscopic layer on the surface ci the coal which, by virtue of the water absorbed thereby, would serve to ley the dust on the coal;

however, thecorronve eect of calcium chloride upon metallic equipment with which the coal ever, to eiiectively dustproo! coal inrthis manner the oil must be uniformly distributed thereon,

which in practice is diilicult to accomplish, particulerly with cosi having surface moisture. Further, the oil treatment tends to be somewhat impermsnent due to absorption oi the oil by the coal with the im nent destruction oi the dustprooiing layer. Since the only practical way of applying the oil to the coal is by spraying the oil thereon, o. considerable iire hazard is engendered bythe use o! such an oilsplay tor treating large quantities of coal. In addition, the oil on the coal tends to stain any surface with which it moy come in contact and does not, therefore. satisfy the demand .oi coal dealers for a,

clean fuel, sven though it may preventthe for mation of dust.

In order to remedy the .above Vdii'ncult'les several 'compositions' have been developed containing which it comes in contact. To the best o f my knowledge, however, none of these compositions A are satisfactory trom sn economic standpoint sud in many cases they are somcwhatdiilicult to prein e form suitable for application to the coal, so that the average mine operator or coal dealer cannot readily be persuaded to employ them. As e, result, e, cheap and eilective composition for dustproong coal is still greatly desired by'the cosi industry.

It is on object otthis invention to provide calcium chloride compositions capable ol being used for dustpr coal without impartingcorrosive characteristics to the coal.

It is another object o this invention to provide calcium chloride'compositions capable o! eii'ectively dustprooilng coni with the consumo.

tion oi sutislly less oi the calcium chloride when calcium chloride alone is used, Another object of this invention is to proylde e, new, eicient and highly economical process for dustproo coal.

' In accordance with this invention coal is dustprooied by the application thereto of an aqueous solution cont calcium chloride and an al haii metal sulfate ci Vun organic alcohol selected from the group t lwci branched-chain primary and secondary alcohols containing from il to 15 carbon atoms, the side chains of which contain not more than 4 csrbon atoms and the hydroml group being'locsted on e. carbon atom other than one o! the corbon atoms or the longest carbon chain of the alcohol, and preierably relatively small amounts o! s. substance which inhibits corrosive action of the calcium chloride. I have surprisingly found that eiective dustprooilng of the coal with the composi` tions of my invention may be eilected with the consumption o! an amount ci the calcium chloride substantially less than the amount of ca1.

cium chloride which would be required to accomplish the same dustproun eect if an aqueous solution of this substance alone Iwere employed;

. 40 therefore, the use' of the compositions oi' my invention for dustproong coal is considerably more economical than the usc of. a straight calcium A chloride solution as heretofore practiced. Fur.-

thermore. tho compositions o! my invention are' more completely absorbed by the coal than varc become corrosive to metallic equipment with compositions containing only calcium chloride and this factor, combined with theiact that less calcium chloride may be used, serves to greatly diminish the inherent corroslveness of such vcorn-v positions so that by the use of my compositions dustp'roof cosi may be produced which is substsntially.non'corrosive. In addition, no innammsbility hazsds. such as are present inthe' treatment oi' coal with oil. are involved in the i application oi.' the compositionsot my inventionsolution containing only calcium chloride.

to coal. The compositions of my invention may be applied to untreated coal or to coal which has previously been treated with oil, as is frequently the case with coal received from mines, since the presence of thesulfated alcohol in my compositions neutralizes the repellent effect normally exerted by oil toward an aqueous solution of calcium chloride. It will be evident, therefore, that because of the simple, safe and economical procedure for dustproong coal provided by the use of the compositions of my invention, these. compositions constitute exceedingly suitable materials for dustprooiing coal on a commercial scale.

The use of an alkali metal sulfate of an organic alcohol selected from the group above set forth is of importance in achieving the desirable results of my invention, since the wetting characteristics of this class of materials are'such that their presence permits the desired reduction in the amount of calcium chloride required to effect dustproong of the coal, efects more uniform distribution of the calcium chloride over the surface of the coal, preventing formation of highly corrosive droplets of calcium chloride solution on the coal, and enhances absorption of the compositions by the coal; chiey because of these factors, coal dustproofed with solutions of calcium chloride containing such sulfated alcohols is considerably less corrosive than coal treated with a These sulfated alcohols display unique propertieswhen admixed with calcium chloride solutions. Thus, for example, tests were conducted in which a definite amount of bituminous coal was placed on the surface of aqueous solutions containing such sulfated alcohols and other sulfated or sulfonated surface active agents, and the time required for the coal to sink. in these solutions measured; the results of tests established that the wetting characteristics of the sulfated alcohols selected rom the above group were not appreciably better than, and in some cases were definitely in-l ferior to, other sulfated or sulfonated surface active agents, several minutes being required for the coal to sink in each case. However, the same amount of-.coal sank in solutions containing calcium chloride and a small amount of a sulfated alcohol of' the above type with extreme rapidity, e. g., 30 seconds in one test; calcium chloride alone is not responsible for this unusual effect -since the coal remained floating indenitely in a straight calcium chloride solution of the same concentration. These tests also established sulfated or sulfonated surface active agents which do not fall within the above group cannot satisfactorily be used in admixture with calcium Vchloride since they are either not soluble in the calcium'"chloride solution, react with the calcium chloride present in this solution to form inf soluble '.-calcium salts which precipitate, or, if

Y soluble such solutionswithout the formation of'calciuml precipitates, they do not have wetting characteristics such that amarked reduction of -`the'amount of calcium chloride needed to dustto be treated. ,'Howeven other-sulfated alcohols ondary alcohols containing 11 to 15 carbon atoms, the side chains of which contain not more than 4 carbon atoms and the hydroxyl group being located on a carbon atom other than the terminal carbon atoms of the longest carbon chain of the alcohol, may also be employed; as an example of such substances there may be mentioned 3,8 diethyl nonanol-6 and 3-ethyl 8-methyl decanol-S.

The corrosion inhibitor preferably employed in accordance with my invention maysuitably-be a soluble chromium compound having inhibiting action, preferably a hexavalent chromium compound such as sodium or potassium dichromate. However, other hexavalent chromium compounds such as ammonium or sodium chromate or complex salts containing ammonium and chromium may be employed as well as organic chromiumcontaining inhibitors such as the chromglucosates. Furthermore, other inhibitors such as those extracted from the destructive distillation of organic products and sold under the name of Rodines may be utilized.

The proportions of the ingredients in my novel compositions may vary considerably. .Thus for example, the amount of the sulfated alcohol present in the compositions may vary, depending particularly upon the type of coal treated, since if a porous coal, such as Iliinois coal, is to be treated, less of the sulfated alcohol should be used than when a. relatively nonporous coal, such as Pocahontas coal, is dustproofed; however, generally an amount of sulfated alcohol equivalent to from 0.03% to 2.0% of the total solid content of the compositions is suitable. The proportion of the corrosion inhibitor preferably included in the'composltions may vary, depending upon the effectiveness of the particular inhibitor employed, but generally between about 0.03% and about 2.5% of the total solid content of the compositions is suitable.v The calcium chloride content may Vary" from 70% to 99.9% of the total solid content of the compositions.

Aqueous solutions of the compositions of my invention may be prepared in a form for direct application to coal by simply adding calcium chloride, the sulfated alcohol and, asis preferred, the corrosion inhibitor to a suitable amount of water and agitating the mixture so as to form a solution. However, from a marketing standpoint it is desirable to make up solid compositions containing the calcium chloride, sulfated alcohol and, preferably, the corrosion inhibitor for sale to coal dealers who may then prepare the aqueous solutions for treating the coal by merely dissolving the mixtures in water. Such solid compositions may be prepared by merely admixing the various ingredients, provided the sulfated alcohol is in solid form and not in an aqueous solution, to form a homogeneous mass. Frequently, however, it is desirable to ,utilize an Vaqueous solution of the sulfat'ed alcohol, since sulfated alcohols of the 'above type areusually derivedY from alcohols selected from the'group 'consisting of branched-chain primary Vand secmarketed in the form of their aqueous solutions by the manufacturers thereof. In such a. case the compositions may be prepared by mixing the aqueous sulfated alcohol solution'with an inert .water-soluble material such as salt, sugar or lignin waste (Goulac) in order to form a paste, and then blending the paste with the remaining ingredients of the composition. Furthermore, the small amount of the sulfated alcohol solution required for use inthe preparation of my compositions may, if desired, :be added directly to the center of the desired amount voi. ca .slum

asrasaa chloride, whereby it becomes absorbed therein without liqueiying the mass. The composition may also be formed into briquettes in any suitable manner and sold as such.

The aqueous solution containing the calcium chloride compositions of my invention may be applied to the coal in any suitable manner, preterably by spraying the coal therewith, although the coal may be dipped inthe solution, drained and permitted to dry, if desired. The coal so treated may be substantially as mined or may have oil vcompcsitions containing about one-half the amount of calcium chloride that would be required to eiect dustproong of the coal if a solution containing the same concentration of calciumchloride alone were used. None oi the substances contained in my compositions detrimentally aiects the combustibility of the coal.

In view of the above it will be evident the compositions of my invention constitute an important forward step in the art of dustprooi'lng coal and, hence, vwill be of interest to those engaged in the marketing of this important fuel in a clean, dustless condition.

Since certain changes may be made in carrying out the above process and certain modifications alcohols containing from 1l to l5 carbon atoms, the total number of carbon atoms in the side y, chains being not in excess of 4 and the hydroxyl group being located on a carbon atom other than the terminal carbon atoms of the longest carbon chain of the alcohol.

4. A composition for dustproong coal compris'ing calcium chloride and relatively small amounts of a chromium compound which inhibits the corrosive action of calcium chloride and an alkali metal sulfate'of an organic alcohol lselected from the group consisting of branched-chain primary and secondary alcohols containing from 11 to 15 carbon atoms, the total number of carbon atoms in the side chains being not in excess of and the hydroxyl group being located on a carbon atom other than the terminal carbon atoms of the longest carbon chain of the alcohol.

5. A composition for dustprooiing coal comprising calcium chloride and relatively small amounts of sodium dichromate and the sodium sulfate of '7-ethyl 2-methyl undecanol-.

6. A composition for dustprooiing coalcomprising between about 70% and about 99.9% calin the compositions which embody vthe `invention may be made without departing from its scope, it is intended that all matter contained in the above description shall be interpreted ias-.illustrative and not in a limiting sense.

l. A composition for dustprooiing coal comprising calcium chloride and relatively small amounts of 'an alkali metal sulfate of an organic alcohol selected from the group consisting vof -branched-chain primary and secondary' alcohols' containing from 11 to 15 carbon atoms. the total number of carbon atoms in the side chains being not in excess of 4 and the hydroxyl group being located on a carbon atom other than the terminal the longest carbon chain of the and secondary alcohols containing from l1,to 15 carbon atoms, the-total number of carbon atoms in the side chains being not in excess of 4 and the hydroxyl group being located on -a carbon atom other than the terminal carbon atoms of th longest carbon chain of the alcohol. 3.' A composition for dustprooiing coal comprising between about 70% and about 99.9% calcium chloride, between about 0.03% end about 2.5% of a substance which inhibits the corrosive action of calcium chloride, and' between about 0.03% and about 2% of an alkali. metal sulfate of an organic alcohol selected from the groupcou-` sisting of branched-chain primary and secondary for dustproong coal colu-v cium chloride, between about 0.03% and about 2.5% sodium dichromate, and between about 0.03% and about 2% of the sodium sulfate of 'I-ethyl Z-methyl undecanol-4.

7. An aqueous solution for dustprooflng coal containing dissolved therein a composition comprising calcium chloride and relatively small amounts of an alkali metal sulfate of an organic alcohol selected from the groupl consisting of branched-chain primary and secondary alcohols containing from l1 to 15 carbon atoms, the total number of carbon atoms in the side chains being not in excess of 4 and the hydroxyl group being located on a carbon atom other` than the terminal carbonrv atoms of the longest carbon chain of the alcohol.

8. An aqueous solution for dustproong coal containing dissolved-therein a composition comprising calcium chloride and relatively smallamounts of a substance which inhibits the corrosive action of calcium chloride and an alkali metal sulfate of an organic alcohol `selected from the group consisting of branched-chain primary and secondary alcohols containing from 11 to 15 car- Abon atoms, the ytotal number of carbon atoms-in' the side chains' being not in excess of 4 and the hydroxyl group being located on a carbon atom other than the terminal carbon atoms of the v' longest carbon chain ofthe alcohol.

. tween about '70% and about 99.9% calcium chlof ride, between about 0.03% and about 2.5% of a substance which inhibits the corrosive action of calcium chloride, and between about 0.03% and about 2% of an alkali rn'etal sulfate of an organic alcohol selected from the group consisting of branched-chain primaryand secondary alcohols containing from 1l to 15 carbon atoms, the total number' of carbon atoms in the side chains being not in excess of 4 and the 'hydroxyl group being located on a carbon atom other than the terminal carbon atoms of the longest carbon chain of the alcohol.

' 10. An aqueous solution for dustprooiing coal containing dissolved therein s. composition comprising calcium chloride and relatively small amounts of sodium dichrcmate and the sodium sulfate of 7-ethyl 2-methyl undecmol-4.

11. An aqueous solution for dustprooilngv coal containing dissolved therein between about and about 50% of'a composition comprising between about '70% and about 99.9% calcium chloride, between about 0.03% and about 2.5% sodium dischromate, and .between about 0.03% and about 2% of the sodium sulfate of 'Z-ethyl 2-methyl` undecanol-4.

12. A process for dustprooiing coal which comprises applying thereto an aqueous solution of a composition comprising calcium chloride and relatively small amounts of an alkali metal sulfate of an organic alcohol selected from thegroup consisting of branched-chain primary and secondary alcohols containing from 11' to 15 carbon atoms, the total number of carbon atoms in the side chains being not in excess of 4 and the hydroxyl group being located ona carbon atom other than the terminal carbon atoms of the longest carbon chain of the alcohol.

13. A process for dustproong coal which comprises applying thereto an aqueous solution of a.

composition comprising calcium chloride and relatively small amounts of a substance which inhibits'the corrosive action of calcium chloride and an alkali metal sulfate of an organic alcohol selected from the group consisting of branchedchain primary and secondary alcohols containing from il to 15 carbon atoms, the total number of carbon atoms in the side chains being not in excess of i and the hydroxyl group being located on a canbon atom other than the terminal carbon atoms of the longest carbon chain of the alcohol.

14. A process for dustproong coal which com- A prises applying thereto an aqueous solution of a composition comprising between about 70% and about 99.9% calcium chloride, between about 0.03% and about 2.5% of a substance which inhibits the corrosive action of calcium chloride,

and between vabout 0.03% and about 2% of an4 alkali metal sulfate of an organic alcohol selected from the group consisting of branched-chain primary and secondary alcohols containing from 11 to 15 carbon atoms,.the total number ot carbon atoms in the side chains being not in excess of 4 andthe hydroxyl group being located on a carbon atom other than the terminal carbon atoms of the longest carbon chain of the alcohol.

15. A process for dustprooflng coal which comprises applying thereto an aqueous solution of a composition comprising calcium chloride and relatively small amounts of a chromium compound which inhibits the corrosive action of calcium chloride and an alkali metal sulfate of an organic alcohol selected from the group consisting of branched-chain primary and secondary alcohols containing from 11 to 15 carbon atoms, the total number of carbon atoms in the side chains being not in excess of 4 and the hydroxyl group being located on a carbon atom other than the terminal carbon atoms of the longest carbon chain of the alcohol. f

16. A process for dustprooflng. coal which comprises spraying the coal with an aqueous solution containing between about 10% and about 50% of a composition comprising calcium chloride and relatively small amounts of sodium dichromate and the sodium sulfate of 'I-ethyl 2-methyl undecanolA.

17. A process for dustprooflng coal which comi prises spraying the coal with an aqueous solution containing between about 10% `and about 50% of a composition comprising between about and about 99.9% calcium chloride, between about 0.03% and 'about 2.5% sodium diohromate, and between about 0.03% and 2% of the sodium sulfate of 'l-ethyl 2-methyl undecanol-4.

JOHN FRED MILLER. 

